Clogged air conditioner under water intake

[KEND]

I have a 1991 33" Carver Aft cabin 3307 , every time I go into a weedy marina my clam shell intake gets clogged and my air conditioner pump does not work properly or shuts down, other boats in the marina do not have the same problem, once i leave the marina the problem goes away, is there a flaw in the design of the intake on my Carver, or any other idea why it would happen,

 

[pdecat]

my carver had a mushroom inlet. grass and junk did get into the strainer but I figured that is what it was for. put a garden hose up against the outlet next time and it will blow out the clog.

 

[jtybt15]

...or if it allows it, turn it around 180*